European Union leaders on Thursday held out membership to Balkan states that emerged from the former Yugoslavia in the 1990s.

The offer comes at a time when the possibility of Ukraine one day joining the European Union has set off a conflict with its former Soviet master Russia and soured East-West relations.

German chancellor Angela Merkel, who leads Europe’s strongest economy, told reporters after conferring with Balkan leaders in Berlin, “We want a speedy progress in the accession process of Western Balkan countries. Slovenia and Croatia are already EU members,” she said, “and others have made quite considerable progress.”

European Commission president José Manuel Barroso added, “This is in our joint political, economic and geostrategic interest. This is the right way to defend the long-term prosperity of all the citizens in our European family.”

Leaders from Albania, Bosnia and Herzegovina, Croatia, Kosovo, Macedonia, Montenegro, Serbia and Slovenia were present at the Berlin summit.

Since the last major European Union expansion in 2004, when eight former Soviet republics and satellite states joined, skepticism about moving the body’s borders ever further east has mounted in Western European countries. Bulgaria and Romania nevertheless joined in 2007 while Croatia became a member last year.

Given the pervasive corruption in Balkan states, political instability in some and shimmering ethnic conflicts in nearly all of them, following a series of bloody civil wars in the 1990s, it seems unlikely either will be admitted into the European Union any time soon.

But European leaders hope that the prospect of membership will encourage liberal economic and political reforms in these countries, as it did in the former Soviet states that joined during the last decade and as it has in Turkey.

Germany supported the secession of Catholic Croatia and Slovenia — which were both once part of the Austrian Empire — from Yugoslavia when it was dominated by Serbia, a Russian ally, and later sponsored their entry into both the European Union and NATO.

The possibility of Europe admitting both Serbia and Kosovo, a breakaway Serbian republic only Western countries have recognized as an independent state, could aggravate its relations with Russia. When it was due to sign an association agreement with Ukraine, which would have moved that country out of the Russian sphere of influence, Russia invaded the Black Sea peninsula of Crimea and annexed the territory. It has since supported a separatist rebellion in the east of Ukraine.

After a change of government, Ukraine nevertheless signed the European treaty, which commits it to the gradual approximation of its economic, judicial and security policies to those of the European Union, last month.